How to Make lima beans pasta casserole

boil 4 cups of water in a saucepan, add some salt,and the shell pasta to it.add one teaspoon of oil to it.cook the pasta till it has a bite to it(not raw,neither too soft).drain the water,retaining about 4-5 tablespoons of the pasta water.
in a separate saucepan heat oil and add thinly sliced onions,add a little salt and saute till it gets a brown colour (caramelise the onions).

add the spices and saute for a min or 2. add the tomatoes , lima beans(washed)and frozen peas and cook for 5-7 mins.add the pasta and toss well.remove from heat.
preheat the oven to 350*F.
add half the amount of bread crumbs and mix.

place the pasta mixture at the bottom of a dish.

use half the amount of mozzarella cheese and layer on top of the pasta mixture

add another layer of pasta mixture.
layer the remaining amount of bread crumbs on top.

layer the remaining amount of cheese on top.
bake for 20 mins or till the cheese melts completely.